Simulated adipose tissue

ABSTRACT

Simulated adipose tissue is provided by heat coagulation of an aqueous emulsion of lipid material having protein fibres dispersed therein, formed using at least one emulsifying protein isolate, egg white and gelatin in defined proportions as the emulsifying and coagulating agents. The heat coagulated material has good oil release on cooking and in the mouth and may be flavored for any desired end use. A bacon analog utilizing the simulated adipose tissue as the white (fat) phase thereof is described.

This is a continuation of application Ser. No. 088,493 filed Oct. 26,1979 now U.S. Pat. No. 4,388,333.

DESCRIPTION

1. Technical Field

The present invention relates to simulated adipose tissue.

2. Background Art

Adipose tissue (animal fat) is naturally present in a variety of meatproducts such as, bacon, steak, chops and roasts. Adipose tissue is alsoused in a variety of processed meat products, such as, breakfast sausageand meat snacks. The adipose tissue imparts a number of beneficial andhighly acceptable properties, such as oil release on cooking and in themouth. However, the ever diminishing lands available for grazing andgrowing feed for animals has intensified the search for satisfactorysimulated meat products having comparable properties to the naturalanimal product.

DISCLOSURE OF INVENTION

The present invention relates to a simulated adipose tissue which isbased on heat coagulable proteinaceous emulsifiers, fibrous proteins andedible lipid material, preferably of non-animal source. The product ofthis invention has the appearance and properties of adipose tissue andmay be used in a variety of food products.

The oil release characteristics of the product are determined by the"fry-away", i.e., the weight loss on frying, which results on frying ofslices of the product. The fry-away generally is in the range of about25 to about 70% by weight.

The non-meat proteinaceous emulsifiers and coagulants used in thisinvention are constituted by a mixture of precisely limited relativeproportions of egg white, gelatin and at least one emulsifying proteinisolate.

The proportions of the components which may be used in the simulatedadipose material provided in accordance with this invention may varyover a wide range, depending on the desired end properties of theproducts. The general and preferred ranges are set forth in thefollowing Table I:

                  TABLE I                                                         ______________________________________                                                     General Range                                                                            Specific Range                                        Component      % by weight                                                    ______________________________________                                        Lipid material about 65 to  about 70 to                                                      about 80     about 75                                          Water          about 15 to  about 18 to                                                      about 25     about 23                                          Proteinaceous  about 2.5 to about 3.0 to                                      emulsifiers-overall                                                                          about 7.0    about 5.0                                         Protein isolate                                                                              about 1 to   about 1.5 to                                      (dry)          about 4      about 2.5                                         egg white      about 1 to   about 1 to                                                       about 2.5    about 1.75                                        gelatin        about 0.1 to about 0.3 to                                                     about 1.0    about 0.5                                         Protien fibres about 15 to  about 15 to                                                      about 45     about 20                                          ______________________________________                                    

The emulsifying protein isolate may be any convenient protein isolatehaving fat emulsifying properties. It has been found that differentprotein isolates produce different oil release and texturecharacteristics, and mixtures of such materials may be used to providethe desired combination of properties. Suitable protein isolates includesoy protein isolate and a portein micellar mass (known hereinafter as"PMM").

PMM is a unique protein isolate, the formation of which is described inour Canadian Pat. No. 1,028,552 and involves a controlled two-stepoperation, in which, in the first step, the protein source material istreated with an aqueous food grade salt solution at a temperature ofabout 15° to about 35° C., a salt concentration of at least 0.2 ionicstrength, generally about 0.2 to about 0.8, and a pH of about 5.5 toabout 6.5 to cause solubilization (or salting-in) of the protein,usually in about 10 to about 60 minutes, and, in the second step, theaqueous protein solution is diluted to decrease its ionic strength to avalue less than about 0.1.

The dilution of the aqueous protein solution, which may have a proteinconcentration, for example, up to about 10%, w/v, causes association ofthe protein molecules to form highly proteinaceous micelles which settlein the form of an amorphous highly viscous, sticky, gluten-like micellarmass of protein. The protein micellar mass so produced is referred toherein as PMM and is used to form the protein fibers. The wet PMM may bedried to a powder and the drying may be effected in any convenientmanner, such as, spray drying, freeze drying or vacuum drum drying.

Improvements in the procedure described in Canadian Pat. No. 1,028,552may be made to increase the yield of the unique protein isolate from theaqueous protein solution.

The protein materials from which the wet PMM is formed may vary widelyand include plant proteins, for example, starchy materials, such as,wheat, corn, oats, rye, barley and triticale; starchy legumes, such as,field peas, chickpeas, fababeans, navy beans and pinto beans; and oilseeds, such as, sunflower seeds, peanuts, rapeseed and soybeans; animalproteins, such as, serum proteins; and microbial protein, i.e., singlecell proteins. Preferably, the protein source is a plant material owingto the readily-available nature of these materials.

The mild processing operations effected on the source protein to formthe PMM ensure that the protein isolate is in a substantiallyundenatured form, as determined by differential scanning calorimetry.

Apart from the protein isolate, the remainder of the emulsifier mix isprovided by egg white and gelatin. It has been found that all threecomponents are necessary to provide a product having good dimensionalstability, good sliceability and good oil release during cooking.

Thus, if gelatin is omitted entirely, the product is soft andnon-sliceable whereas if the overall gelatin concentration is too high,then a hard, low oil release product is obtained. Gelatin alone does notproduce emulsification.

Similarly, combinations of protein isolate and gelatin alone formproducts which are soft and lacking in sliceability while egg white andgelatin alone produce a rubbery mass with no fat-like quality and no oilrelease. All three components, therefore, are required.

The weight ratio of these various proteins at the same overall proteinlevel may be varied considerably to control the final texture from softto hard. The greater the proportion of egg white present, the drier isthe product with less oil release while the greater the proportion ofprotein isolate present, the more fat-like the product becomes withgreater oil release.

The fibrous protein used in the product of this invention may be anyconventional texturizing fibrous protein, but preferably is the proteinfibres formed from PMM by injection of a PMM into hot water. The fibrousprotein provides a structure closely resembling adipose tissue and addstexture, mouth feel and strength to the product.

In addition, the protein fibres increase the overall protein content ofthe product while the fibres do not significantly decrease oil releaseon cooking although some decrease in oil release is experienced withincreasing concentrations of fibres. The fibres, therefore, represent asubstantially inert protein filler with respect to fat binding. Thepresence of the protein fibres thus enables the overall protein level ofthe product after oil release on cooking to increase to a high level,for example, about 15 to about 30 wt. %, without resulting in acake-like texture and without having to use high cost protein materials.

Protein fibres of various dimensions may be employed in the product ofthe invention, generally of length of about 0.5 to about 15 cm,preferably about 1 to about 4 cm, and of diameter of about 0.1 to about1 mm. Mixtures of fibres of differing dimensions may be used to providevariable texture.

The edible lipid material may be any convenient edible lipid materialcapable of emulsification in water with the mixture of emulsifiers andis usually at least one edible oil, preferably from a non-animal source,such as a vegetable oil, which may be unsaturated.

The simulated adipose tissue is formed by dissolving and/or dispersingthe proteinaceous emulsifiers in water, emulsifying the edible lipidmaterial with the proteinaceous dispersion incorporating the fibrousprotein in the emulsion in dispersed form, and then heat setting theemulsion to a fat-like solid material consisting of a heat-coagulatedmatrix of protein with entrapped lipid material having protein fibresdispersed therethrough.

The fibrous protein may be incorporated into the emulsion in anyconvenient manner, such as by direct addition thereto or by dispersingthe same in the aqueous emulsifier dispersion. It is usually preferredto add the fibres to the emulsion to avoid degradation under the usuallyhigh shear conditions of emulsion formation.

The degree of emulsification achieved and hence the final texture of theproduct can be controlled to a certain degree by variation of certainparameters during the emulsification step.

For example, the pH of the emulsifier dispersion can affect theemulsification capacity of the proteins. The aqueous dispersion,therefore, is usually adjusted, if necessary, to a pH of about 6.5 toabout 8.0, preferably about 7.0 to about 7.6, prior to commencingemulsification.

Variations in the temperature at which emulsification occurs also variesthe degree of emulsification, with greater emulsification occurring at40° C. than at ambient temperature (20° to 25° C.). This difference inemulsification leads to a higher oil release from a product produced ata higher emulsification temperature.

The presence or absence of sodium chloride also has an effect onemulsification. Since sodium chloride tends to increase dispersion ofthe proteins and the more dispersed the proteins, the more availablethey are for emulsification, it is preferred to provide small amounts,generally up to about 3.5% by weight, preferably about 1 to about 2.5%by weight.

The emulsification is usually effected under conditions of high shearfor at least part of the procedure, although high shear can lead to overemulsification and destabilization if prolonged. Usually, a high shearmixing of about 5 to 15 minutes is adopted with a final low shear mixingbeing effected for about 5 to 15 minutes.

Depending on the desired end use of the simulated adipose tissue,flavourings of any type may be incorporated into the product byinclusion of the same in the emulsion prior to heat setting.

The emulsion is heat set by heating to an elevated coagulatingtemperature, generally in the range of about 90° to about 120° C. with asuperatmospheric pressure being applied, if necessary, at the upper endof this range. It has been found that the texture of the product varieswith the coagulating temperature, with a firmer product being obtainedat the higher temperatures.

The simulated adipose material provided in accordance with thisinvention has the appearance and feel of adipose tissue and exhibits fatrelease on cooking so that no additional oil is required. The productalso exhibits fat release in the mouth which together with the fibroustexture give a good mouthfeel to products incorporating the simulatedadipose material.

The simulated adipose tissue of this invention may be used in a varietyof products as a simulated meat fat material, such as in chunk form invarious food products, such as meat snacks and dried sausages, or as thewhite phase of a bacon analog material.

In U.S. Pat. No. 3,840,677, assigned to General Foods Corporation, thereis described a bacon analog product comprising a fatty or white phaseand a lean or red phase. A new bacon analog product is provided by acombination of the simulated adipose tissue of this invention as thewhite phase and a red phase having the composition set forth in the U.S.patent, as outlined in the following Table II:

                  TABLE II                                                        ______________________________________                                                    General Range                                                                            Preferred Range                                        Component      % by weight                                                    ______________________________________                                        Water         about 40 to  about 45 to                                                      about 65     about 60                                           Fat           about 10 to  about 15 to                                                      about 25     about 25                                           Protein isolate                                                                             about 6 to   about 9 to                                                       about 24     about 18                                           Albumen       up to about 15                                                                             about 1 to                                                                    about 8                                            Proteinaceous 0 to about 15                                                                              about 1 to                                         filler                     about 10                                           Colour and    to taste (usually                                                                          about 5 to                                         flavouring    5 to 15)     about 10                                           agents                                                                        Thickening agent                                                                            0 to about 2 0 to about 1                                       ______________________________________                                    

As described in the prior patent, a bacon analog product is obtained bylayering emulsions corresonding to the red phase and white phase in thedesired thickness and then heat coagulating the layered emulsions. Theresulting coagulated material has good sliceability and is sliced to thedesired thickness.

The use of the simulated adipose material of this invention as the whitephase results in a simulated bacon analog which crinkles and has goodtexture on cooking, and has good oil release for frying without addedcooking oil or fat.

BEST MODE FOR CARRYING OUT THE INVENTION

The invention is illustrated by the following examples:

EXAMPLE I

This Example illustrates the formation of a simulated adipose tissue inaccordance with this invention and the use thereof in a bacon analog.

A formulation for a simulated adipose tissue was chosen, as follows:

    ______________________________________                                        Component        Wt. %                                                        ______________________________________                                        Fababean PMM     2.50                                                         Egg white solids 1.00                                                         Gelatin          0.33                                                         Sodium chloride  2.00                                                         Water            21.50                                                        Vegetable oil    72.67                                                                         100.00%                                                      Protein fibres   30 wt. % of                                                                   above                                                        Spices and flavours                                                                            as required                                                                   for taste                                                    ______________________________________                                    

The fababean PMM (i.e., a PMM prepared from fababeans in accordance withthe process of Canadian Pat. No. 1,028,522) was dispersed with sodiumchloride in 80% of the water, the pH was adjusted to about 7.6, and themixture was solubilized for 30 minutes. The gelatin was dispersed in theremaining 20% of the water, heated to about 40° C. to solubilize thesame and cooled to about 30° C. prior to addition to the fababean PMMdispersion. The egg white solids were then added to the protein mixture,the pH again adjusted to about 7.6, and the mixture was solubilized forabout 15 minutes.

Rehydrated (in water) thawed fresh fababean PMM fibres of diameter about0.4 mm and length of about 0.5 to about 2 cm were added to thesolubilized mixture along with water soluble spices and flavours.Two-thirds of the oil was then blended (or homogenized) with the proteinand fibre mixture at high shear for 10 minutes after first dissolvingoil soluble flavours in the oil.

The mixture was transferred to a Hobart Kitchen Aid™ mixer, and theremaining oil was blended in at speed 8 for 10 minutes. The resultingemulsion was layered into pans with lean phase bacon analog as describedin U.S. Pat. No. 3,840,677 and heat set for 1 hour in flowing steam. Theheat-set slab then was tempered for 12 to 24 hours at about 4° C.

The tempered slab was sliced to desired thickness and fried at 177° C.(350° F.) for time varying from 4 to 8 minutes providing different finaldoneness and texture. No oil was added and satisfactory oil release wasobserved. The cooked bacon analog exhibited good taste characteristics,as compared with natural bacon.

EXAMPLE 2

In this Example, PMM materials from other protein sources, namely peaPMM, peanut PMM and soybean PMM were substituted for the fababean PMM inthe formulation and the procedure was repeated. Results equivalent tothose obtained in Example I were obtained in each case.

EXAMPLE 3

In this Example, the PMM fibres were rehydrated in protein solution madeup from PMM. The overall firmness of the white phase appeared to beincreased.

EXAMPLE 4

This example illustrates the variation in texture of the bacon analogproduct with varying quantities and sizes of PMM fibres.

The procedure of Example 1 was repeated, except that the quantity of thefibres was varied over the range of 15 to 45% by weight of the remainderof the composition and fibres of diameter 0.4 mm and 0.1 mm were used invarying proportions of 40 to 70 wt. % of large diameter fibres to 60 to30 wt. % of small diameter fibres.

The texture of the product varied from crunchy to chewy.

EXAMPLE 5

This Example illustrates the variations in properties of the bacon whitephase in the bacon analog product formed following the procedure ofExample 1.

The procedure of Example 1 was repeated except that the relative weightproportions of PMM and egg white were varied while the overall proteinweight remained the same and the properties of the bacon white phasewere observed. The following Table III summarizes the results obtained:

                  TABLE III                                                       ______________________________________                                        Egg   PMM                      Oil Release                                    wt. %      Colour     Texture      on cooking                                 ______________________________________                                        0     3.5      Brownish   Soft, lacks                                                                              --                                                                 stablity, not                                                                 sliceable                                           0.875 2.625    Off-white  Soft, sliceable                                                                          High oil                                                           but lacks  release                                                            cohesiveness                                        1.75  1.75     Slight     Fat-like, texture                                                                        Good                                                    yellow     slightly rubbery                                                                         oil                                                                           release                                  2.625 0.875    Yellowish  Dry, crumbly,                                                                            Little                                                             rubbery texture                                                                          oil                                                                           release                                  3.5   0        Yellow     Very rubbery,                                                                            No oil                                                             crumbles when                                                                            release                                                            fried                                               ______________________________________                                    

At overall weight proportions of 2.5 wt. % protein isolate, 1 wt. % eggwhite and 0.33 wt. % gelatin, varying proportions of a PMM and a soyprotein isolate (Promine D™) were used in the bacon white phase and theoil release properties determined. When 100% PMM was used, the fry-awayvalue was 26 wt. % and increased with increasing proportions of soyprotein to a value of 44 wt. % at 100% soy isolate. It was also observedthat the cooked material became more crumbly as the proportion of soyisolate increased.

INDUSTRIAL APPLICABILITY

In summary of this disclosure, the present invention provides asimulated adipose tissue having many desirable properties and wideutility. Modifications are possible within the scope of this invention.

We claim:
 1. A sliceable simulated bacon product consisting of a heatcoagulated mass of separate red and white layers, said red layerconsisting essentially of the following components in recitedpercentages by weight:

    ______________________________________                                        Water               about 40 to about 65                                      Fat                 about 10 to about 25                                      Protein isolate     about 6 to about 24                                       Albumen             up to about 15                                            Proteinaceous filler                                                                              0 to about 15                                             Colour and flavouring                                                         agents              to taste                                                  Thickening agent    0 to about 2                                              ______________________________________                                    

and said white layer consisting essentially of the following componentsin recited percentages by weight:

    ______________________________________                                        Lipid material      about 65 to about 80                                      Water               about 15 to about 25                                      Proteinaceous emulsifiers,                                                                        about 2.5 to about 7.0                                    said proteinaceous                                                            emulsifiers consisting of:                                                    (i) Protein micellar mass                                                                         about 1 to about 4.0                                      (ii) Egg white, and about 1 to about 2.5                                      (iii) Gelatin       about 0.1 to about 1.0                                    Protein fibres      about 15 to about
 45.                                     ______________________________________                                    


2. The bacon product of claim 1 wherein the red layer consistsessentially of the following components in recited percentages byweight:

    ______________________________________                                        Water               about 45 to about 60                                      Fat                 about 15 to about 25                                      Protein isolate     about 9 to about 18                                       Albumen             about 1 to about 8                                        Proteinaceous       about 1 to about 10                                       filler                                                                        Colour and flavouring                                                                             about 5 to about 10                                       agents                                                                        Thickening agent    0 to about 1                                              ______________________________________                                    


3. The bacon product of claim 2 wherein the white layer consistsessentially of the following components in recited percentages byweight:

    ______________________________________                                        Lipid material      about 70 to about 75                                      Water               about 18 to about 23                                      Proteinaceous       about 3.0 to about 5.0                                    emulsifiers                                                                   Protein micellar mass                                                                             about 1.5 to about 2.5                                    Egg white           about 1 to about 1.75                                     Gelatin             about 0.3 to about 0.5                                    Protein fibres      about 15 to about 20                                      ______________________________________                                    